The ratio of an amount of heat, dQ, transferred to a body in some process to the
corresponding change in the temperature of the body: C = dQ/dT. The heat capacity
depends upon the mass of the body, its chemical composition, thermodynamic state, and the
kind of process employed to transfer the heat. The word "capacity" may be misleading
because it suggests the essentially meaningless statement "the amount of heat a
body can hold," whereas what is meant is the heat added per unit
temperature rise. → specific heat.

Assuming that the Universe is a thermodynamically → isolated system,
a state of absolute uniformity in the Universe in which all
temperature differences would reduce to zero and no energy will be available for use,
according to the → second law of thermodynamics.
In that condition of maximum → entropy,
the Universe would be in a state of unchanging death.
First introduced by the German physicist Hermann von Helmholtz (1821-1894) in 1854, on the
basis of William Thomson's (1824-1907) idea.